I wonder if Java supports the same regex futures as Perl does (look ahead, look behind, .....).

Also, that article doesn't give any information of the test script whatsoever, for example:

  while (<FILE>) {
    m/xyz/;
  }
[download]

Will/Should be slower then

  $regex = qr/xyz/;
  while (<FILE>) {
    m/$regex/;
  }
[download]

Also, the regex that is used in that article seems (at first look) not a very well written regex...